Hydraulic feed control panel



l1=e|.'24,1942. K. R. HERMAN m1, 2,274,603 y l HYDRAULIC FEED CONTRQLPANEL Filed July 26, 1.937 5 Sheets-Sheet 1 Nwe um,

NM. .SU m. ///M y m'.. lll: mm/

z* v1 w? @wma OM,

INVENTRS neth 7?.-/erman Tvy ATTORNEYS Feb. 24, 1942'. AK, R, HERMAN E-l-AL HYDRAULIC FEED coNTRoL Pague;

Filed July 26, V i937 l5 Sheets-Sheet 2 [li/IA VIII/lll Feb. 24, 1942; Y

l K. R. HERMAN ETAL HYDRAULIC 'FEDy CONTROL PANEL M mfwwm j QW //////ymwa- Feb. 24, 1942. K. R. HEMAN ETAL 2,274,603

HYDRAULIC FEED CONTROL PANEL Fileduuly 2e, 195'? 5 sheets-sheet- 4 r K.R. HERMANl ETAL. HYDRAULlc FEED CONTROL PANEL Feb. 24, 41942.

Filed July 26, 1957 5 Sheetvs-SheefI 5 N u N Mmm BY L. Raymond Wyman75mm u v m NN NN I nv 7 A'TTORNEY.

Patented Feb. 24, i942 HYDRAULIC CONTROL PANEL Kenneth R. Herman, FerrisT. Harrington, and L. Raymond Twyman, Detroit, Mich., assignors toVickers,lncorporated, Detroit, Mich., a corporation of Michigan'pplication July 26, 19437, Serial No. 155,652

This invention relates to improvements in a hydraulic feed control panelto be used for regulating the speed and directionof the reciprocatingpart of a machine tool, actuated by a double acting piston and cylinder.

An object of the present invention is to furnish a control unitapplicable to drilling, reamlng, boring, turning, milling and equivalentmachinev tool cycles which is adaptable to a Wide vari ty of cyclerequirements it being capable of p oviding any cycle sequence as madevup of rapid advance, adjustable coarse feed, adjust-` able'fine feed,jump rfeed and rapid return motions. I

Another object of the. invention is to provide a control unit whichallows smooth and accurate feed rates. regardless of cutting toolresistance or coarse to ne feed is accomplished by diverting the flowthrough the coarse feed throttle from the tank return to the flnefeedthrottle and then to the tank, placing thetwo in series and causing thefine feed throttle t'o be effective.

A further feature of the invention allows a rapid traverse of themachine tool with a pump of half the ordinary volume by using adifferential ycylinder traverse action in which pressure liquid isfurnished to both sides of the piston and traverse rates' areproportional to piston area less Ychanges in hydraulic operationpressure. This is accomplished by the arrangement Aofthe circuits whichplace's the throttle valves in 'series with the exhaust flow of a doubleacting cylinder. An advantage of this control unit is that it may beused with a'number of different typesof pumps,

piston rod area. The invention is also adapted to be used with a`nautomatic reversing arrangement with 4a time delay or remote controlstarting system, if desired.

An important feature is the simplicity of design of the panel whicheliminates a plurality of valves leaving only two moving parts with no'elaborate linkage or latch devices. Other adthe choice depending on thetype available and the requirements of the particular machine cycle rateis maintained which is unaffected by changes in pump slippage. A

Another advantage of the present control panel over previous controldevices, is that, in the shifting of the valve from one position toanother to effect changes in the speed of the cycle, there is nopossibility of va blindspot between the stages of theV cycle, since thecoarse and fine feeds are in series andthe 'speed control isaccomplished by directing exhaust flow through throttle valves.

lSince a hydrostatic valve or pressure governor is arranged in serieswith coarse` and ne feed throttle valves, exhaust oil from the cylindermotor passes through the throttle valves toa tank return line in thesequence named when a feed selector valve 4is ir. a position so thatline feed is in progress. AThe coarse feed throttle valve is noteffective at this time due to the fact that the opening through the sameis of greater area than that of the fine feed throttle. Movement of thefeed selector valve connects the'oil 'exhausting from the coarse feedthrottle directly to the tank return line, making the fine` feedineffective without interruption of the ow from vantages will beapparent in the course of the description.

In the drawings:

Fig. 1 is a cross-section of the control panel showing all thepassageways in the same plane for purposes of illustration. This panelaffords differential action in Vrapid traverse forward.4

Fig. 2 illustrates the use of the control panel irr a hydraulic machinesystem using a constant delivery pump.

Fig. 3 is a cross-section of -a controll panel with a different valvespool to provide nondiiferential rapid advance. I

' Fig. 4 illustratesthevariable delivery pump which is preferablyinstalled in the system of Fig. 2 in lieu of the xed displacement pump.

Fig. 5 shows Va lcross-section of the variable delivery pump.

Figs. 6, 7, 8 and 9 are cross-sections of the panel as shown ln Fig. 1with the valve in stop, second feed, first feed, and rapid forwardpositions, respectively. e

Referring to Fig. 2, a constant delivery pump 5 driven by a motor 6 isarranged to furnish liquid under pressure to a control panel 1 which isoperably connected by liquid pressure lines to a conventionaldifferential or compound cylinder 8. The liquid, which is supplied by atank 9, is preferably oil and will hereafter be referred to as oil.Contained in cylinder 8 is a; slidable piston Ill having a piston ro'dll directly connected to a reciprocating Work table I2 of a machinetool. Cams I3, Il and l5 are mounted on the working table I2, in suchrelation to the control panel l as tocontact and actuate the stem of acontrol er selector .valve I6 at various stages in the cycle of themachine tool.

'I'he selector valve stem I6 is assembled in the housing of the controlpanel 1, as shown in Fig. 1, and is adaptedto be shifted axially in thepanel .to effect rapid advance, first and second feeds, reversal, andstopping of the cycle. A lever I1, located on the panel 1, isoperatively connected to the valve stem HiA to permit 'the operatormanually to shift the valve to any position. Two adjustable throttlevalves I8 and I9, located in the panel housing 1, are operated from theface of the panel by any standard locking type dials'29 and 2l shown inFig. 2. A ow control or hydrostatic valve 22, also positioned inthecontrol panel housing and circuit, is of the type disclosed .inBritish Patent No. 399,609, of June l2, 1931.

The control panel can best be described by setting forth its operationin the hydraulic system of Fig. 2.

`In the operation: Oil under pressure is furnished by the pump through arelief valve When the table reaches the end' of its stroke, theIoperator shifts the handle i1 and the valve I6 downward to reverseposition as shown in Fig.

K 1. The rofl end of the cylinder is then open to 25, and a conduit 26to a pressure inlet line 21 in the housing 1. With the valve stem I 6shifted to rapid forward position in its extreme uppermost positionshown in Fig. 9, oil under pressure passes through line 21, ports 2B and29, and

- ton area and the rod area for a faster speed of the piston. This is arapid traverse portion of the cycle and it continues until cam I4depresses the valve stem IIS and pushes the selector valve downward toa"first speed position shown in Fig. 8. Pressure is then directed tothe'piston kend of the cylinder as before through line21, ports 28 and29 and line 30, but the rod end of the cylinder is now closed to thepressure source and. is open to the tank 9 through the line 32, apassageway 33, theflow control valve 22, throttle valve I8, lines 34 and35, ports 36, 4I and 31, and lines 38 and 39. The effect of the throttlevalve I8 being in series with the exhaust'iiow from the rod and of thecylinder 8 will be a restriction in the exhaust flow and a consequentreduction in the feed rate of the working table.-l .This stage of thecycle is called the ,coarse feed stage.

'I'his coarse feed continues until the cam I3 depresses the valve stemI6 to a second feed More specically, the flow from the rod 4end of thecylinder is through lin'es 32' and 33,iow control valve 22 throttleValve I8, lines 34 andv 34a throttle valve I 9, a passageway 40, a port4I, port 31 and thence through lines 38 and 39 to the tank. The throttlevalve' I9 is designed to provide a ner adjustment than that of valve I8.The coarse throttle I8 takes the flow through itself but does notrestrict .or control iow when in ne feed.

the pressure source through lin'e 21, ports 28 and 3l', and line32,-thus causing the piston Il) to be moved upwardly at a rapid rate tostarting posi/tion. During this reverse traverse, the piston end of thecylinder is connected to the tank line-39 through line 39, port 29, a.port 42 and 'passageways 43 and 44.

As the table reaches its starting 4positionpthe cam I5 pulls the valvestem I6 into stop" position shown in Fig. 6. The pressure line 21 andboth ends of the cylinder 8 are then open to the tank so as to unloadthe pump until the valve stem is again shifted to restart the cycle.

The exhaust fiow of the rod end of the cylinder is always open to theupper side of the flow control valve 22 through'the passageway 44 and a-passageway 45. This flow control valve serves to maintain a constantpressure differential across the throttle valve or valves I8 and I9' asdescribed in Ythe previously mentioned British patent.

The circuit just described with the constant displacement pump is thepreferred circuit for the control panel, since, with the differentialaction in the rapid traverse stroke, le'ss volume of pressure liquid isneeded, and consequently a smaller pump may be'used.

A modification of the control panel `is shown in Fig. 3. The housing andthe various elements therein are exactly the same as that shown anddescribed with Fig. 1, and the panel may be used in a circuit shown inFig. 2. The valve stem, however, designated 46 is formed with differentspools than the valve stem I6 of Fig. 1 and will produce a slightlydifferent circuit.

When the handle I1 is in rapid forward position, pressure passes throughthe line 21, ports 28 and 29, and line 3|] to the piston end of thecylinder 8 just as in the previous modification. The rod end of thepiston, however, instead of being connected to the pressure source, asin the previously described panel, is connected to the tank through line32, ports 3l, 36, 4I and 31, and lines 38 and 39. Fig. 4 shows a housing41 of a variable delivery pump and the conduits 26 and 39 of the systemin Fig. 2 would enter the pump housing 41 as indicated. A variabledelivery piston pump such as that shown in Fig. 5, to be describedlater, would be used in the housing 41.

It will be understood that either control panel may be used with aconstant delivery pump and relief valve or a variable delivery pistonpump with pressure stroke control, and that the operating valve I6 or 4Bunloads the pump entirely when the cycle is completed. This minimizesthe power input to the system during normal op` Ieration. Thediiferentialtraverse action panel,

however, represented lby Fig. 1, allows theuse of a pump havinga-smaller maximum volume.

For. instance, by using a rod having approxi-v mately half the area ofAthe cylinder, a rapid .traverse can be obtained by using a pump-havingarea equals the area of the piston minus the area. of the rod. Whereas,in the differential traverse action panel theeffective area in bothrapid *which`l is fastened directly to the drive shaft 56.

forward and rapid reverse movements is onehalf the piston area.

By a comparison of the panel villustrated lin Figure 1 with thatillustrated in Figure 3 it will be seen 'that the only difference is inthe spacing and length of the various lands and grooves on the valvespools I6 and 46, respectively. Thus the same body and coring for theentire panel may be used with a spool s'uch as I6 in Figure 1 to providethe differential rapid traverse action or may be used with a spool suchas 46 in Figure 3 to provide the non-differential rapid traverse action.This feature entails considerable economy in production cost wherepanels f vboth types .arerequ'ired for various installations.Furthermore, it expedites changeovers in a given machine fromdifferential rapid traverse action to non-differential rapid traverseaction by merely substituting a different spool.

It will be seen that with the speedv control throttles both in serieswith the exhaust from the cylinders during the feed.y strokes, there isleliminated the possibility of changes in feed rate due to changes inpump slippage. ment also prevents tools fromI jumping ahead whenbreaking through the work and thus refsults in longer tool life.

This arrange- When the vertical arrangement is used, as l shown in Fig.2, a counterbalancemay be used as at 48, or, as an alternative, aby-pass and check valve 49 located in the conduit 32 leading from therod end of the cylinder. This valve 49 places a hydraulic restriction inthe line 32 leading from the lower end of the cylinder to the panelsuflicient to balance the weight of the slide, elective only when flowis in the downward direction, and the check valve in the unit 44 permitsfree or unrestricted flow from the panel to the cylinder to raiseor'return the slide. If a horizontal rather than a vertical installationwere desired, these counterbalance devices could be dispensed with.

-If desired, the system may be provided,-in the following manner, kwithan automatic reverse:

A cam may be arranged to contact a reversing switch 5I at the end of therst'half of the cycle.

YThis switch is, located in an electrical circuit originating at L1, Leand containing solenolds 52 and 52a which are operatively connected tothe handle l1, as-diagrammatically illustrated in Eig.

2. When the reversing cam 50 closes switch 5|,

the solenoid 52 will actuate the 'lever I1 and thereby shift the valvestem I6 to reversal position.

The cylinder block 51 and port member 58 are adapted to be held so thattheir center axis forms an angle with the axis of theshaft 56.Consequently, upon rotation of the drive shaft, the pistons will bepushed into and withdrawn from the cylinders 59 as the cylinders andpistons rotate in unison about the axis of the cylinder block 51. Theintake of the pump is shown by a conduit 63 and the outlet by conduit64. The

'angle which the cylinder block forms with the driving shaft iscontrolled by a pressure stroke compensator 65 which consists of amovable piston, 66 pivotally connected to the port member 58 and thestationary cylinder 61 which is mounted in the side wall of the tank 41.A

spring 68-tends to thrust the piston 66 to its outermostposition in thecylinder 61, thereby moving the pump cylinder block 51 to its maximumoutput position. A conduit 69 leading from the pressure in the system tothe cylinder 61 furnishes liquid under pressure to the piston 66 andtends to move the same downward against the action of the spring 68,thereby reducing the volume output of the pump. It will be seen thatwith the use of this pump, illustrated in Fig. 5, the'volume output ofthe variable delivery pump will be directly proportional to the pressurerequired at the cylinder motor and in case of an abnormal rise inpressure in the system, the volume output of the pump will be reduced tozero.

We claim the following:

1. In a hydraulic systemv of the type having a pressure source, a doubleacting hydraulic motor provided with two ports for pressure liquid, anda member to be reciprocated by said motor,

a control panel comprising a housing provided with a longitudinall Valverecess, pressure and tank lines connected to said recess, linesconnecting said motor ports with said recess, a slidable valve stern insaid valve recess, said valve stem being movable to connect said motorports alternately with said pressure and tank lines, means on saidreciprocating member f or Where a delayed reverse is necessary, an elec-4 tric time delay device 53 may be incorporated in the electric circuitof Fig. 2.` The electric con-'- trol also allows the insertion of aregiote control starting switch 54 for actuatingsolenoid 52a, and anemergency reverse switch-55. 'I'his will permitremote control of thelmachine at point out of reach of the lever l1. l

The variable delivery pump 'previously re v 'ferred to i connect-ionIwith-the control vpanel is' shown in etail in Fig. 5, The drive shaft56 is vrotated from any` convenient source of power and is mounted in ananti-friction bearing supported by a side Wall ofthe tank 41.f Amultiple plunger rotary pump is actuated by the' -motor port isconnectedwith the pressure port,

the speed of the reciprocating member being directly dependent on thenumber of throttle valves in series in the exhaust flow.

2, In a hydraulic system of the type having a pressure source,I ardouble acting hydraulic motor provided with two ports for pressureliquid, and a member to be reciprocated by said motor,

a control panel lcomprising a housingl provided with a longitudinalvalve recess, pressure and tank lines connected to said recess, -linesconnecting said motor ports with said recess, a slidable valve stem in`saidvalve recess, said valve stem being movable to connect said' motorports alternately with said pressure and-tank lines, cam means on saidreciprocating member for actuating said valve stem at various stages" ofthe cyclev of movement of .said reciprocating member, and coarse and nefeed throttle valv'es y in said panel, said throttle valves beingarranged to be selectively connected in series in the ex- -double actinghydraulic motor provided with two ports for pressure liquid, a variablespeed reciprocating member operated by said motor, a control panelcomprising a housing provided with a longitudinal valve recess, pressureand vtank lines connected to said recess, lines connecting said motorports with said recess, a slidable valve .stem in said valve recess,said valve stem being movable to-connect said motor ports alternatelywith said pressure andl tank lines, a hydrostatic flow control valve, acoarse fe'edthrottle valve, and a fine feed throttle valve, said valvestem `being so arranged that consecutive movements thereof will connectone of the motor ports with the pressure line, and will connect theexhaust ow from the other motor port to the tank line, respectivelythrough the flow-control valve and the `coarse feed throttle valve inseries with Athe exhaust flow and through the iiow control-v valve andthe coarse and fine feed throttle' valves in sries with the exhaust now.

4. In a hydralic system having; a pressure source, a double actinghydraulic motor provided Y with two ports for pressure liquid, anda-variable speed reciprocating member connected for operation by saidmotor, means for controlling the rate and direction of movement of saidmember to effect starting, stopping, and a series of constant feed ratesinthe progression of the cycle of the reciprocating member comprising ahousing provided with a longitudinal valve recess, a slidable valve stemin said valve recess,

said valve stem being movable to connect said motor ports alternatelyWith said pressure and tank lines, ahydrostatic'flow control valve, acoarse feed throttle valve, and a fine feed throttle valve,'said valvestem and lines connected thereto being so arrangedthat pressure may bedirected to both cylinder ports to effect a differential rapid traverseaction, and such that a. shifting of said valve stem to variouspositions will connectone of the motor .ports with the pressure port,and will connect the exhaust ow from the other motor port to the tankthrough the iiow control valve and the coarse feed throttle valve inseries to eiect coarse feed and through the ow control valve and thecoarse and iine feed throttle valves in seriesto eiect fine feed, andwill eifect'reversal by connecting pressure and tank lines connected tosaidrecess. 0

lines connecting said motor ports with said recess, said valve stembeing movable to connect said motor ports alternately with said Pressureand tank lines, a hydrostatic flow control valve, a coarse feed throttlevalve, and a fine feed throttle valve, and adjustable cam means on saidreciprocating part for contacting and shifting said valve stem to itsvarious positions at the various stages of the cycle, said valve stembeing so arranged that consecutive movements thereof will connect one ofthe motor ports with the pressure line, and will connect the other motorport to the tank line, respectively through the iiow control valveandthe coarse feed throttle' valve in series, and through the iiowcontrol` valve and the coarse and fine feed throttle valves in series..l

5. In a hydraulicsystem havnga pressure source, a constant deliverypump, a double acting power cylinder provided with a port at each Icluding rapid traverse, coarse feed, fine feed, and

rapid reverse, said means comprising a housing provided with alongitudinal valve recess, a

slidable valve stem in said valve recess, presthe last named motor portto the pressurev port and the other motor port to the tank.

6. In a hydraulic system, means for supplying liquid under pressure, ahigh pressure conducting line, an exhaust pressure conducting line forlreturning spent liquid to the source, a double 'member substantially atthe ends of the reciprocable movement of said member to alternatelyconnect the two conduits leading to the motor to the high and Aexhaustpressure lines, a plurality of restricted orifices in the control uniteach having a different degree of restriction,

'passageways in the control unit interconnecting the orifices and thevalve chamber, and means on the reciprocable member for shifting thevalve member at various stages in the cycle of movement of the saidreciprocable member for successively connecting the orifices in seriesin exhaust flow through the exhaust pressure line from one of theconduits leading to the motorwhile the other conduit leading to themotor is connected to the high pressure line, said'oriflces beingarranged so that the resistance to vexhaust ow increases depending onthe number of orifices in series.

7. In a hydraulic system, a motoroperable by the introduction of liquidunder pressure, a line for conducting liquid under pressure to saidmotor, a line for conducting displaced liquid away from said motor, amember shifted by the motor, and .means comprising a plurality ofrestricted orifices, each having a different degree of restriction, andvalve means for controlling the direction of iiow to and from the motorand for selectively connecting one or more of said orifices in series inone of said conducting lines to selectively increase the resistance offlow through said line depending on the number of orifices in series,and thereby decrease the rate of movement of the member, and a singlehydrostatic `flow control valve connected to regulate the rate of owthrough said orifices under varying loads in accordance with the numberof orifices connected in said line at any one time.

8. In a" hydraulic system, a motor operable by the introduction ofliquid under pressure, a lin'e for conducting liquid under pressure tosaid motor, a line for conducting displaced liquid away from said motor,a member shifted by the motor, and means comprising a plurality ofrestrictedorices, veach having a diierent degree of restriction, ahydrostatic flow control valve f arranged to maintain a constantpressure drop across any-member of said orices, and valve means forcontrolling the direction of flow to andfrom vthe'motor and forselectively connecting one or more of said orifices in series with saidhydrostatic valve in one of said conducting lines to selectivelyincrease the resistance of ow through said line depending on the numberof orifices in series, and thereby decrease the rate of movement of themember.

9. A unitary control panel for controlling the movements of ahydraulically operated machine toolA slide to give rapid advance, feed,and rapid return movements to a hydraulic motor supplied with pressurefluid from a single source of the said connections, ,a rapid return anda stop, and a control member shiftable between four positions foroperating said valve member.

11. A unitary control panel for controlling the movements of ahydraulically operated machine tool slide to give rapid advance, feedand rapid return movements to a hydraulic motor supplied with pressurefluid from a single source of the type which delivers fluid at apredetermined maximum rate or at whatever lesser rate it may be consumedand which is controlled solely by l ltype .which delivers fluid at apredetermined maximum rate or at whatever lesser .rate it may beconsumed and which is controlled solely by the pressure head againstwhich fluid is delivered,` said panel comprising` in combination a valveblock having only four outside connection ports including pressure and Aexhaust ports and a pair of motor ports, means entirely selfcontainedwithin the block for limiting uid 'flow to a predetermined adjustablefeed rate, said means including an adjustable throttle and automaticmeans for maintaining constant the pressure drop through the .throttlefor all settings of the latter, shiftable Valve means in the block forselectively establishing flow paths be' tween said ports and the flowlimitingy means to provide a rapid advance by connecting the pressureport to a motor port, a feed by connecting the pressure port to the samemotor port and the exhaust port to the other motor port with the flowlimiting means in one of said connections, a rapid return anda/stop,'and a single control member lshiftable between four positions foroperating said valve'means.

10. A unitary control panel for controlling the movements of ahydraulically operated machine tool slide to give rapid advance, feed,and rapid return movements to a hydraulic motor supplied withpressurefluid from a single source of the type which delivers fluid .ata, predetermined maximum rate or at'whatever lesser rate it may I beconsumed and which is controlled solely by a single valve in said blockand having valvev ports communicating with said outside. ports and withlthe iiow limiting means, a unitary valve member shiftable betweenfour-*positions for se' lectively establishing ow paths through saidvalve ports `between said other ports and the ow .limiting means toprovide a rapid advance by connecting the pressure -port to a motorport,l a feed by connecting the pressure port to the same motor port andthe exhaust port to. the other motor port with 'the ow limiting means inone of the pressure head against which fluid is delivered, said motorbeing of the cylinder and piston type, said panel comprising incombination a valve block having only four outside connection portsincluding pressure and exhaust ports and a pair of motor ports, means'inthe block for limiting fluid ow to a -predetermined adjustable feedrate, and a single valve in said block, said block having Avalve portscommunicating with said other ports and with the flow limiting means,said valve ports including only one port connected through the blockwith one of the motor ports, said one port lying adjacent and between avalve port connected tothe pressure port and a valve port havingcommunication with the exhaust port, whereby a shiftable valve memberhaving lands to connect said one port with the pressure port and blockit from the exhaust port while connecting the other motor port with thepressure port, will provide differential rapid advance action, and ashiftable valve member of different form having lands to connect saidone port with the exhaust port and block it from the pressure port whileconnecting the other motor port with the pressure' port, will providenondiiferential rapid advance action, said other valve ltype whichdelivers fluid at a predetermined maximum rate or at whatever lesserrate it may be consumed and which is controlled solely by the pressurehead against which fluid is delivered, said panel comprising incombination a valve block having only four outside connection portsincluding pressure and exhaust ports and a pair of motor ports, means inthe block and governed solely by the fluid passingthrough the block forlimitingiiuid flow to a constant but adjustable feed rate under allvariations of motor load, shiftable valve means inthe block forselectively establishing flow paths between said ports' and the flowHunting means to provide a rapid advance by connecting the pressure portto a motor port, a feed by connecting the pressure port to the samemotor port and the exhaust port to the other motor port with the flowIlimiting means Vin one of said connections, a rapid return and a stop,and a single control member shiftable be tween four positions foroperating saidvalve means.

KENNETH R. HERMAN.

FERRIS 'I'. HARRINGTON.

L. RAYMOND TWYMAN.

